双定位像结合Care Dose 4D和Care kV技术在降低肺部CT辐射剂量的临床应用价值

目的 探讨双定位像结合Care Dose 4D和Care kV技术在肺部CT检查中的可行性及其临床应用价值。方法 连续纳入临床确诊为肺部肿瘤行肺部CT扫描的患者60例，按随机数表法分为对照组和试验组，每组各30例，对照组行单定位像（AP）结合Care Dose 4D和Care kV技术扫描，试验组行双定位像（AP和lat）结合Care Dose 4D和Care kV技术扫描。由2位高年资医师采用双盲法对两组图像和病变组织的信噪比（SNR）、对比噪声比（CNR），及整体图像质量进行综合分析和评价，同时计算有效辐射剂量。结果 60例患者均成功完成肺部CT检查，试验组整体图像质量评分为4.57±0.45，与对照组的4.73±0.45相比差异无统计学意义（P>0.05）。对照组图像SNR、CNR、病变组织SNR、CNR与试验组相比差异均无统计学意义（P>0.05）。试验组和对照组的容积CT剂量指数CTDI_vol、剂量长度乘积（DLP）、有效剂量（E），差异有统计学意义（t=8.514、8.464、8.464，P<0.001）。与对照组相比，试验组有效剂量降低了33.3%。结论 较单定位像（AP）肺部CT检查，双定位像（AP和lat）结合Care Dose 4D和Care kV技术肺部CT检查可获得满足诊断及临床需求图像，同时明显降低辐射剂量，可成为肺部CT常规检查方式。

The clinical value of anteroposterior and lateral scout image combined with Care Dose 4D and Care kV in reducing radiation dose of chest CT scanning

Objective To investigate the feasibility and clinical value of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV in chest CT scan.Methods A total of 60 patients of clinical diagnosis with lung tumor were enrolled. Those patients were randomly divided into test group and control group. Control group underwent a scan protocol with lateral scout scan combined with Care Dose 4D and Care kV, while anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV were performed in test group. The signal-to-noise ration (SNR), contrast-to-noise ratio (CNR), and overall image quality of two groups of images and diseased tissues were analyzed and evaluated by two high-grade radiologists using double-blind method. Effective doses (E) were also calculated. Results All the 60 patients had successfully completed the chest CT scans. Test group overall image quality (4.57±0.45) and control group overall image quality (4.73±0.45) had no statistically significant difference (P>0.05). The control group image SNR, CNR and diseased tissue SNR, CNR compared with test group had no statistical significance difference (P>0.05). The difference of the volume CT dose index (CTDI_vol), dose-length product (DLP) and effective dose (E) of test group and control group was statistically significant (t=8.514,8.464, 8.464, P<0.001). Compared with control group, the effective dose of test group decreased by 33.3%. Conclusions Compared with lateral scout scan, the technology of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV can decrease radiation dose without reducing the image quality. This technology can therefore be considered as a regular imaging modality for chest CT scan.